[PATCH 2/2] sha1_name: fix error message for @{<N>}, @{<date>}

[Ramkumar Ramachandra <artagnon@gmail.com>]

Currently, when we try to resolve @{<N>} or @{<date>} when the reflog
for the current branch doesn't go back far enough, we get errors like:

  $ git show @{10000}
  fatal: Log for '' only has 7 entries.

  $ git show @{10000.days.ago}
  warning: Log for '' only goes back to Tue, 21 May 2013 14:14:45 +0530.
  ...

The empty string '' looks ugly and inconsistent with the output of
<branch>@{<N>}.  Replace it with the string 'current branch'.

Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 sha1_name.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sha1_name.c b/sha1_name.c
index 416a673..683b4bd 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -517,6 +517,10 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 		}
 		if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
 				&co_time, &co_tz, &co_cnt)) {
+			if (!len) {
+				str = "current branch";
+				len = strlen("current branch");
+			}
 			if (at_time)
 				warning("Log for '%.*s' only goes "
 					"back to %s.", len, str,
-- 
1.8.3.rc3.6.ga9126d5.dirty